TPO Silicone

TPO Silicone is a Kool Coats restoration system that coats a prepared thermoplastic polyolefin (TPO) roof with KF-600 KoolFlex high solids silicone. It is for the USA market, and its coating chemistry is silicone. The system is aimed at low-slope TPO roofs, with waterproofing and standing-water resistance as its focus.

The existing membrane stays in place under the coating. The system is one of the silicone roof coatings offered for single-ply roofs.

TPO is cleaned and repaired, adhesion is tested, and the specified primer is used wherever required. Compatible detail work is completed, and KF-600 is applied to the selected film build. Later coating repairs and recoats use compatible silicone.

• Primer: P-301 Multipurpose Primer, which bonds to TPO, PVC and metal
• Detail material: KF-460 KoolFlex Mastic
• Coating: KF-600 KoolFlex high solids silicone

KF-600 is a single-component, moisture-cure elastomeric silicone with 95% volume solids and a specific gravity of 1.30 plus or minus .04. It has a 5,000-hour accelerated weathering rating of PASS and a low-temperature mandrel bend of pass at -15 degrees F.

• Tack-free time: 1 to 2 hours
• Recoat cure time: 24 hours
• Final cure time: 30 hours
• Initial tensile strength: 266 psi at 73 degrees F and 247 psi at 0 degrees F
• Elongation after 5,000 hours of aging: 194% at 73 degrees F and 229% at 0 degrees F
• Wet adhesion to SPF: 2 pli or more
• Temperature stability range: -67 to 350 degrees F
• Initial SRI value: 109
• Dry coat thickness: 20 mils

The recommended application rate on most substrates is 1.5 gallons per 100 sq ft. The coating is sprayed with an airless unit rated for at least 3500 psi at the gun head and 3 gallons per minute, or it is rolled with a medium-nap roller. A brush is used on small touch-up work.

Damaged membranes, flashings and penetration points are repaired and sealed before application, and low ponding areas are repaired. The material is mixed until uniform in color and consistency, with a power mixer for quantities over one gallon. Thinners and other additives change the intended performance and void warranties.

KF-460 is a 100% silicone mastic that goes on by trowel, brush or putty knife in a 1/8 to 1/4 in layer to repair cracks, breaks, tears and holes. It can be applied over old, cured silicone coatings and sealants, and the voids left in patched areas are filled before coating. Most topcoats go on once the mastic is thoroughly set.

• Solids by volume: 53%, by weight: 60%
• Tensile strength: 300 psi, with 250% nominal elongation
• Weight per gallon: 11.8 lbs
• VOC: 50 g/L
• Service temperature of the cured film: 15 to 180 degrees F
• Application temperature: 50 to 100 degrees F
• Cure time: 24 to 48 hours at 77 degrees F and 50% humidity

P-301 builds mils on the TPO surface and smooths cracks. It is 51.4% solids by volume and 51.12% by weight, nominal, and weighs 8.36 lbs per gallon. It blocks asphalt oils from bleeding through silicone systems. The application temperature is 40 to 120 degrees F, VOCs are 22 g/l, and full cure takes about 4 hours at 77 degrees F and 50% relative humidity.

KF-600 is not applied below 40 degrees F or when rain is expected within four hours, and the coating can dry in 1 to 4 hours. Full System Limited Warranties for KF-600 range from 5 to 20 years. The mastic is covered by the Kool Coats 10-20 year Material Warranty, with a fee-based Labor and Material option. The roof is inspected at least twice a year and after severe weather.

The silicone TPO system is a single, thick application of KF-600 with no fabric or layering. The system is used only where the TPO passes adhesion testing. It is recoated only with silicone, and the coating shows minimal chalking.

KF-600 is a single-component, moisture-curing silicone rubber roof coating for low-slope roofs. It is made in white, gray and tan and comes in 1 gallon, 5 gallon and 50 gallon sizes. It is rain-safe in 1 hour. Listed substrates include smooth-surface BUR, granulated cap sheet, well-adhered acrylic coatings, concrete, metal, sprayed-in-place polyurethane foam and various single-ply membranes.